1. Field of the Invention
This invention relates generally to improved ester compositions, and more particularly to benzoate esters of castor oil, hydrogenated castor oil, ricinoleic acid, and hydroxy stearic acid useful as diluents, solvents, emollients, solubilizers, liquid carriers, vehicles, and the like for cosmetic and toiletry formulations.
2. Description of the Related Art
Esters and acids are known for a variety of different applications for cosmetic, pharmaceutical and medicinal purposes.
For example, U.S. Pat. No. 1,553,271 to SHONLE describes benzyl esters of higher fatty acids, e.g. 10 or more carbon atoms, such as lauric, capric, palmitic, stearic, oleic and linoleic acids. The compounds may be used as "therapeutic" agents. It is preferred to used mixed fatty acids for a lower cost product. The general structure is R--COO--CH.sub.2 --C.sub.6 H.sub.5, wherein R is an alkyl group containing 9 or more carbon atoms. The benzyl esters of higher fatty acids are prepared by reacting the anhydrous alkali salt of the fatty acid with benzyl chloride in a suitable solvent. This reference does not teach the benzoate esters of stearates or ricinoleates or the 12-hydroxy compounds thereof.
U.S. Pat. No. 2,182,397 to ECKEY describes a process for forming ether derivatives of polyhydric alcohols, including derivatives that contain esterified fatty acid groups. The reaction calls for reacting a polyhydric alcohol in a quantity of a carboxylic acid which is only sufficient to esterify a portion of the hydroxyl groups of each molecule of the polyhedric alcohol entering into the reaction, thus leaving one or more hydroxyl groups in each molecule unesterified. A small quantity of an esterifying catalyst is added. Polyhdric alcohols listed are, e.g. glycerol and the glycols, e.g. ethyl, propylene, trimethylene, and sorbitol and inannitol. The carboxylic acids listed include aromatic acids, such as benzoic acid. Eckey does not teach the preparation of benzoic acid esters of fatty acids.
U.S. Pat. No. 2,942,013 to BRUSON describes reacting halogenated phenols in the presence of an alkaline catalyst with a salt of 9,10-epoxystearic acid to form a salt of halogenated mono-aryl ether of 9,10-dihydroxystearic acid. The compound is called a 9,10-disubstituted stearic acid wherein one substituent is hydroxyl and the other is a halogenated aryloxy (Col. 1, lns. 46-49). The halogenated phenols may have alkoxy as a nuclear substituent. The reference does not teach the preparation of benzoic acid esters of fatty acids.
U.S. Pat. No. 3,012,049 to BILL describes the use of a hindered phenol as catalysts for carboxylic ester-interchange reactions of fatty acid alkyl esters by using lower C-chain alkyl esters of benzoic acid. The reactions are limited to those in which the starting material and the end product are substantially free of unesterified carboxyl groups. (col. 2, lns. 34-37). The reference does not teach the preparation of double esters of fatty acids or triglycerides.
U.S. Pat. No. 3,116,305 to MORRIS describes reacting 3,5-dialkyl hydroxybenzyl alcohols with carboxylic acid to produce esters (col. 2, ln. 55) which have antioxidant properties, miscibility in organic substrates, and sunscreening characteristics. The acids may be alkenoic acids, aliphatic dicarboxylic acids, fatty acids and aromatic acids having up to two rings. Examples include acetic, butyric, caprylic and undecanoic as well as stearic and ricinoleic acids. The reactions are specifically between substituted aromatic alcohols and aliphatic acids. The --OH of ricinoleic or hydroxy stearic acid is not esterified. The reference does not teach the reaction of benzoic acid on the --OH group of the castor based fatty acids backbone in the form of triglycerides (castor oil) or hydrogenated castor oil (castor wax) or ricinoleic acid fatty alkyl ester or hydroxy stearic acid alkyl ester.
U.S. Pat. No. 3,322,772 to TOGASHI et al. describes a process for production of carboxylic acid esters. Benzoic and stearic acids are listed as possible carboxylic acids and polyhydric alcohols (polyols) such as glycerol and aromatic alcohols such as benzyl alcohol are listed as possible alcohols. The reference does not teach or suggest preparation of double esters.
U.S. Pat. No. 3,459,736 to DALIBOR describes a process for producing ester plasticizers using titanium-peroxide containing catalysts. The preparations are polyesters with polyhydric alcohols or polycarboxylic acids or aromatic dicarboxylic acids/anhydrides. Among the alcohols which may be reacted with the carboxylic acids are ricinoleic acid, ricinoleic mono-, di-, triglyceride and ricinoleic methyl ester (col. 4, lns. 45-50). The reference does not teach or suggest preparation of monomeric esters that are double esters of the castor triglycerides or of the --OH containing castor based fatty acids.
U.S. Pat. No. 4,597,906 to UHRIG et al. describes preparations of esters of aromatic alcohols specifically beta-naphthols with fatty acids, transesterified with glycerol and further ethoxylated. The preparation of castor oil-beta-naphthol, its oxyethylation product and its sulfosuccinic acid semiesters is described. The --COOH group of the fatty acids is reacted with either aromatic alcohol such as beta-naphthol or polyhydric alcohol for further ethoxylation. The reference does not teach or suggest preparing double esters using the --OH group of fatty acids for reaction with aromatic acid, not aromatic alcohol, and the --COOH group with mono alcohol and not polyhydric alcohol.
U.S. Pat. No. 5,227,503 to HAGAN describes cosmetic compositions containing unsaturated 2-hydroxyalkenoic acids as skin, hair and nail treatment compositions.
However, among the foregoing patents, none are directed to compositions of benzoic acid esters of glycerol tri-ricinoleate, benzoic acid esters of glycerol trihydroxy stearate (GTHS), benzoate esters of alkyl ricinoleates or benzoic esters of alkyl hydroxy stearates of the present invention, or the advantages which result from these compositions.